Fill an array with different size vectors

123 views (last 30 days)
I have different sized vectors and an array to fill
A=[1,2,3,4];
B=[5,6];
C=[7,8,9];
ARRAY=zeros(5);
And I want to reach this:
OBJECTIVE =
1 2 3 4 0
5 6 0 0 0
7 8 9 0 0
0 0 0 0 0
0 0 0 0 0
Any idea? Also if there is any way to extend vectors to certain length I highly appreciate to know.

Accepted Answer

Stephen23
Stephen23 on 5 Sep 2019
Edited: Stephen23 on 5 Sep 2019
For an arbitrary number of vectors use a cell array, then looping is trivial:
>> D = {[1,2,3,4],[5,6],[7,8,9]};
>> M = zeros(5,5);
>> for k = 1:numel(D), M(k,1:numel(D{k})) = D{k}; end
>> M
M =
1 2 3 4 0
5 6 0 0 0
7 8 9 0 0
0 0 0 0 0
0 0 0 0 0

More Answers (3)

the cyclist
the cyclist on 5 Sep 2019
Here is one straightforward way:
A=[1,2,3,4];
B=[5,6];
C=[7,8,9];
ARRAY=zeros(5);
ARRAY(1,1:numel(A)) = A;
ARRAY(2,1:numel(B)) = B;
ARRAY(3,1:numel(C)) = C;

Diego R
Diego R on 5 Sep 2019
Thank you both! I'd never had found this "numel" by myslef.

Jos (10584)
Jos (10584) on 5 Sep 2019
A=[1,2,3,4];
B=[5,6];
C=[7,8,9];
[ARRAY, tf] = padcat(A,B,C) % pad with NaNs
ARRAY(~tf) = 0 % replace those NaNs with zeros
PADCAT concatenates vectors of unequal lengths by padding them with NaNs. It is available for free on the File Exchange

Categories

Find more on Creating and Concatenating Matrices in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!